In Hyperledger Fabric when identity is issued the certificate and Key is shared by the admin unlike in multichain where the user receives the key as response and it is not shared with anyone not even admin.
Is it possible in some way in Fabric? If not then Hyperledger is not decentralized it is only distributed.
It is possible. An admin registers a new user by the certificate authority and gets a "secret" back.
This secret is then used by the client to enroll directly by the certificate authority and get his own key/certs, with nobody in between.
Related
Hello I have a Hyperledger Network blockchain network running with 5 organization. If one of the private key of the organization gets compromised what are the steps or methods available to revoke the private key. Are there any mechanisms in Fabric where we can generate new set of key pair for the same organization .
you can generate new set of key pair from your CA for your organization and then you should update the config block. you can take a look at this article to understand the idea.
You can generate the new certificate and private key pair from the Certificate authority and pass it to the configuration. In the meantime, you can add previous the certificate in the Certificate revocation list.
I am a newbie to Hyperledger Fabric. I came across a very confusing part of fabric.
Cryptogen is used to generate certs and keys for users and admin in an organisation.
Talking specifically about fabcar,
A very similar thing is the done by:
enrolling an admin
enrolling and registering a user identity using CA, in fabcar chaincode.
Things got more confusing when I saw CA server creating a bootstrap
'admin' identity while starting of the container itself.
So what exactly is happening?
What is the flow?
What is the difference between these admins created again and again?
I see, CA server container has a volume mounted, pointing back to the crypto-config folder which already have certs and keys generated by cryptogen.
Why are we again creating bootstrap identity on fabric-ca-server start using -b flag? We already have admin certs and keys generated for admin by cryptogen and those are already mounted on the fabric ca server container.
Why are we again enrolling an admin in fabcar chaincode, we already have certs and keys for admin, don't we(from the volumes mounted on fabric ca server container)?
Why are we both registering and enrolling a new user in fabcar chaincode, we already have certs and keys for one user(in fabcar), don't we(from the volumes mounted on fabric ca server container)?
Similar existing answers is not what I am looking for. I want an in-depth insight.
Thanks.
Okay, so after digging around for continuous 1 week I found exact answer to the question.
First, I would like to lay down exact flow and structure of fabric samples applications.
Fabcar and Commercial Paper are two different applications being
provided by fabric as a part of fabric sample.
Fabcar uses first-network and Commercial Paper uses basic-network.
Fabcar has its chaincodes in chaincode folder while Commercial Paper has its chaincodes in contract folder within the two organisations.
After chaincodes are installed by administrators (don't confuse this admin with CA admin, this is simply a developer who is managing channel) using peer chaincode install and peer chaincode instantiate the contract becomes available to all the components of the respective channels.
Now we need to have certain application that will be invoking contracts known to the channel. Both Fabcar and Commercial Paper have their different applications in their respective application folders.
Applications can interact with our channel or say underlying fabric layer through a gateway.
The Hyperledger Fabric SDK provides a gateway abstraction so that
applications can focus on application logic while delegating network
interaction to the gateway. Gateways and wallets make it
straightforward to write Hyperledger Fabric applications. Find here in the docs
Our applications require some identity to be able to use underlying fabric layer. This identity's authenticity is checked by gateway before allowing access to the network.
Fabric uses concept of keys and signed certificates to perform this authentication.
Diving into a different concept here, fabric provides two kind of certification architectures (architecture might not be the correct word),
cryptogen - generally used for developement or testing purposes to generate keys and certificates
Certificate Authority - not a new concept, used by fabric to generate certificates. Any CA server requires to have admin to allow generating certificates.
While bringing up the server itself, this bootstrap identity is created using fabric-ca-server start with a -b option with username:password parameter.
Coming back to fabric, before starting any network (basic-network or first-network) fabric asks us to generate cryto-config.
Commercial Paper uses certificates and keys generated by this previously generated crypto-config by cryptogen to generate identities for the application.
Fabcar uses CA to generate certificates and keys. Admin was registered already when we brought up our CA server container in Fabcar. We simply gave him certs and keys on enrollment. New user require both registration and enrollment (done using CA admin identity).
The private and public key are first generated locally and the public
key is then sent to the CA which returns an encoded certificate for
use by the application. These three credentials are then stored in the
wallet, allowing us to act as an administrator for the CA. Find here in the docs
So it's not by design of fabric why Fabcar used CA and why Commercial-Paper used cryptogen, it's simply by choice.
I'll end my answer, quoting exact statement from the fabric documentation.
When we created the network, an admin user literally called admin
was created as the registrar for the certificate authority (CA).
Our first step is to generate the private key, public key, and X.509
certificate for admin using the enroll.js program. This process uses
a Certificate Signing Request (CSR) — the private and public key are
first generated locally and the public key is then sent to the CA
which returns an encoded certificate for use by the application.
These three credentials are then stored in the wallet, allowing us
to act as an administrator for the CA. We will subsequently register
and enroll a new application user which will be used by our
application to interact with the blockchain. Find here in the docs
addToWallet.js is the program that Isabella is going to use to load
her identity into her wallet, and issue.js will use this identity to
create commercial paper 00001 on behalf of MagnetoCorp by invoking
papercontract. Find here in the docs
Any corrections from experts are very welcome. These are my deductions from code observation.
I don't know what fabcar does, but maybe I can clarify some Hyperledger Fabric concepts to you.
cryptogen is a development tool using for generating all the (MSP and TLS related) cryptographic stuff you need initially for your development Fabric network.
For more serious deployments, you use Fabric-CA instead. Fabric-CA is a Certification Authority that maintains a database of the identities registered for your organization and allow your registered actors to enroll their certificates. You can also update identities, revoke identities and certificates, etc.
And then you have to distinguish a CA administrator from a organization administrator. You first enroll the CA administrator, otherwise you cannot register identities. And a organization admin is simply an identity with role admin for the organization.
Normally, the enrolled CA administrator generates all the identities. After that, later, in other place, the organization administrator (or any other identity) enrolls its certificate by specifying the user and password declared during registration.
Some Theory: cryptogen is just a tool written in golang and what it does is it will create a self-signed root ca and some signed certificates(org admin, users, entities)
Now when you start CA, if you want to use the same cert and key generated by cryptogen then you will use below command
fabric-ca-server start -b myorgadmin:myorgpw -d
ELSE if you do not want to use cryptogen generated certificates then you can use below command and you should forget about cryptogen generated certificates because they no longer use and you have to generate by yourself
fabric-ca-server init -b myorgadmin:myorgpw
DIFFERENCE is init command
Bootstrap CA server credentials are in order to authenticate for future
purposes
Ex: If you want to register a new user then you need to authenticate
with credentials
In future, you can use cryptogen generated user certificates or you can register different users by authenticating CA server
What exactly is difference between enrolling and registering a certificate in Hyperledger Fabric CA. I am new to cryptography and i am really confused about the working of Fabric CA. Also how are certificates generated via cryptogen is diffrent from certificates generated via Fabric CA.
So from what i understand when you "enrol" an identity you get the certificates and private keys for it. When you "register" the identity, you are simply creating the user name and password for that identity with the CA server.
The certificates that the cryptogen tool generate are not any different to the ones generated by the Fabric CA, the cryptogen tool is there for convenience in development. It should not be used in a live / production environment. Under the hood the cryptogen tool actually spins up a fabric ca server locally.
Here is a link to the latest documentation for Fabric CA:
https://hyperledger-fabric-ca.readthedocs.io/en/latest/
"Registration" is done by the CA admin. A username and password is assigned to an identity, along with attributes (will the identity be an admin or a node, for example?). This registration places the username and password, along with the relevant other information about the identity, in the database of the CA. No certificates have been generated at this point. The identity has simply been registered.
"Enrollment" is the process where certificates are created and given to the user of the identity. The username and password is given to this user out of band, and they use the name and password as part of a fabric-ca-client call to the CA. The public and private keys --- encoded with the relevant attributes registered with the CA --- are then generated.
The reason for the separate between registration and enrollment is to ensure that only the user of an identity receives their private key.
The certificates created by a CA are identical to those created by cryptogen --- an x.509 certificate is an x.509 certificate --- but cryptogen is a tool for quickly creating certs in a test environment, not a true method for creating certificates for anything resembling production.
Registering identity means adding its details in Fabric CA.
Enrolling means process when registered identity connects to CA and sends Certificate Signing Request (CSR) to it. CA checks if the identity is registered and performs some other validations, if checks are successful then it returns signed certificate to the identity. Since the certificate is signed by CA trusted by blockchain network, the identity has now means to interact with the network using this certificate.
So, to make the identity being able to interact with the network it must pass two steps in this particular sequence:
Be registered on CA
Be enrolled
Admin is preregistered in CA using when it is started
fabric-ca-server start -b admin:adminpw
The details are here:
https://hyperledger-fabric-ca.readthedocs.io/en/release-1.4/users-guide.html
also you can refer to source
The concept of first register(Saving username,password and other attributes in CA's DB) then registered identity can enroll to get certificates is the same in the latest version of Fabric CA as it was previously.
Refer to the latest link:
https://hyperledger-fabric.readthedocs.io/en/latest/deployment_guide_overview.html#step-four-use-the-ca-to-create-identities-and-msps
"Register and enroll an admin identity and create an MSP. After the CA that will be associated with an organization has been created, it can be used to first register a user and then enroll an identity (producing the certificate pair used by all entities on the network). In the first step, a username and password for the identity is assigned by the admin of the CA."
I found following in the Composer docs. Is it ok? I thought that CA is for storing certificates/public keys but not private keys. Is it possible to sign messages on a client-side?
The Hyperledger Fabric certificate authority generates an enrollment secret that can be given to the participant, who can then use the enrollment secret to request their enrollment certificate and private keys from the Hyperledger Fabric certificate authority.
Yes its possible. Composer stores the key/certificate in a wallet accessible by the client application user, so the user can sign transactions on the business network (using a Composer business network card to connect to it and which has the user's blockchain identity). This transaction is therefore signed by a certificate to say which identity is being used to submit the transaction.
i'm currently working on a POC application using hyperledger composer. I'm creating a mobile app which uses the client-SDK for interacting with my hyperledger network. I'm wondering how authentication works. Enrolling a new user works fine, i can enroll a new user being an admin and i receive the enrollmentID and enrollmentSecret. The documentation tells me the enrollmentSecret is used as confirmation for the CA to generate a certificate and corresponding keys.
The SDK gives me the idea that i'm authenticating by using only the enrollmentID and enrollmentSecret instead of the certificate and keys.
Quoting another answer i found:
When a participant enrols using the enrolment ID and secret, an enrolment certificate is generated and placed into their wallet (configured using the keyValStore property in the connection profile). Once the enrolment certificate has been generated, the enrolment secret is made invalid. The secret can be only used one time - it is not a password.
However what i want to do is give the "identity" total ownership of the certificate and keys so they can use it to authenticate on the network (maybe turn it into physical form / paper wallet). Looking at the SDK documentation this doesn't seem possible and i currently have no idea how it works if the only way to connect to the network is supplying the enrollmentId and secret.
Or does the SDK automatically store and use the certificate in the stored in keyValStore(connection profile) to authenticate? If so is it possible to manage this programmatically?
Thanks in advance
Hyperledger Composer issues new identities by using the Hyperledger Fabric certificate authority (CA) to register new enrollment certificates. The Hyperledger Fabric certificate authority generates an enrollment secret that can be given to the participating identity, who can then use the enrollment secret to request their enrollment certificate and private keys from the Hyperledger Fabric certificate authority.
See https://hyperledger.github.io/composer/unstable/managing/identity-issue.html
You then bind a participant (added to your business network) to that identity and that identity is used to submit transactions to the Fabric blockchain. So the authority to do so is via the metadata in the connection profile (pointer to the KeyValStore for the user in question) and the id's certificate in that KeyValStore.
Check out the Hyperledger Composer docs.
https://hyperledger.github.io/composer/unstable/managing/identity-bind.html